To configure how the Application Server recovers from transactions

Transactions might be incomplete either because the server crashed or a resource
manager crashed. It is essential to complete these stranded transactions and recover
from the failures. Application Server is designed to recover from these failures and complete
the transactions upon server startup.

While performing the recovery, if some of the resources are unreachable the
server restart may be delayed as it tries to recover the transactions.

When the transaction spans across servers, the server that started the transaction
can contact the other servers to get the outcome of the transactions. If the other
servers are unreachable, the transaction uses the Heuristic Decision field to determine
the outcome.

In the tree component select the Configuration node.

Select the Transaction Service node.

To enable the recovery of incomplete transactions, check the Recover in
the On Restart field.

Set the amount of time, in seconds, the Application Server tries to connect
to the unreachable server in the Retry Timeout field. The default value is 10 minutes
(600 seconds).

Set the policy for unreachable servers in a transaction in the Heuristic
Decision field.

Unless there is a good reason to set this field to Commit,
leave Heuristic Decision set to Rollback. Committing indeterminate transactions can
compromise the data integrity of your application.

Click Save.

Restart the Application Server.

To set a transaction timeout value

By default, the server does not timeout a transaction. That is, the server waits
indefinitely for a transaction to complete. If you set a timeout value for transactions,
if a transaction isn’t completed within the configured time, the Application Server rolls
back the transaction.

In the tree component, select the Configuration node.

Select the Transaction Service node.

Enter the number of seconds before the transaction times out, in the Transaction
Timeout field.

The default value of Transaction Timeout is 0 seconds.
This disables transaction timeouts.

Click Save.

Restart the Application Server.

To set the location of the transaction logs

The transaction log records the information about each transaction in order
to maintain the data integrity of the resources involved and to recover from failures.
Transaction logs are kept in the tx subdirectory of the directory
specified by the Transaction Log Location field. These logs are not human readable.

In the tree component, select the Configuration node.

Select the Transaction Service node.

Enter the location of the transaction logs in the Transaction Log Location
field.

A tx subdirectory is created and transaction
logs are kept under that directory.

Click Save.

Restart the Application Server.

To set the keypoint interval

Keypoint operations
compress the transaction log file. The keypoint interval is the number of transactions between keypoint operations
on the log. Keypoint operations can reduce the size of the transaction log files.
A larger number of keypoint intervals (for example, 2048) results in larger transaction
log files, but fewer keypoint operations, and potentially better performance. A smaller
keypoint interval (for example, 256) results in smaller log files but slightly reduced
performance due to the greater frequency of keypoint operations.

In the tree component select the Configuration node.

Select the Transaction Service node.

Enter the number of transactions between keypoint operations in the Keypoint
Interval field.